“A human being can survive just fine living on a diet of hamburgers and fast food.” If you believe this statement to be true and also happen to own a backyard Koi pond, chances are you also believe there is little difference between available fish foods on the market. “A cheap Koi food is the exact same food as the expensive brand with a different label.” This too is another comment often uttered by Koi keepers who choose the diet for their fish based solely on price. And while it is certainly understandable that a pond owner would want to save money, not all fish foods are the same. Below are some of the key factors every Koi keeper should consider when choosing a fish food for Koi and other pond fish.

Nutritional Analysis

You would never go into a restaurant and eat whatever the waiter puts on your plate if you didn’t first know what it was. This same logic should be applied when selecting a diet for your Koi or other pond fish. Different Koi food varieties are formulated for use during different types of the year. All-season food varieties, for example, contain minimal protein content and designed for fast digestion. Growth foods, on the other hand, contain high amounts of protein and are ideal for summer feeding.

Feeding a high growth fish food during the winter can result in serious health issues. As the water temperature drops, the Koi metabolism slows down. Growth foods cannot be easily digested and can literally begin to rot inside the Koi fish, resulting in illness and possible death. Catfish food is designed for short-term feeding of food fish only. These foods were not designed for long-term feeding, nor do they meet the unique nutritional requirements of Japanese Koi.


Many discount fish diets on the market contain fillers, such as corn, which are not highly digestible for Koi and other pond fish. This results in more fish waste being produced, which can cause more work for your pond filter and result in diminished water quality. Whenever possible, it is best to avoid fish foods containing fillers and other low quality ingredients. Many premium Koi food varieties on the market contain ingredients designed to mimic the natural diet of Koi, which are actually ornamental carp, in the wild.

Because many top tier Koi fish food offerings come with a hefty price tag, many pond owners commonly mix different foods together to help provide a healthy Koi diet while limiting the impact on their bottom line. This strategy is extremely popular for Koi keepers with a lot of fish to feed, especially those with larger Koi with equally large appetites. For mixed ponds, those including both Koi and goldfish, this feeding method can also provide a significant savings over feeding a premium quality food exclusively.


In order to maximize economies of scale, most cheap foods are milled in bulk quantities. These foods often sit in a warehouse for up to three years before they are finally sold to a retail customer. As Koi food ages, the nutritional content can deteriorate rapidly. This is especially important for lower quality foods, some of which have minimal nutritional value to begin with. The shelf life of Koi food varies depending on the type of packaging used, but in general it is recommended to use all food within two years from the original mill date.

While choosing a cheap food option is certainly understandable given the state of our economy, it is worth noting that not all Koi diets are created equal. A cheap Koi food is not a premium Koi food without the fancy packaging. This reality can be easily proven by comparing the ingredients and nutritional content of budget foods with name brands offered at a slightly higher price.